The invention relates to a system and a method for controlling an ultrasound generator of a machine tool for generating ultrasound for machining a workpiece. According to the invention, a determined phase shift of the ultrasound is analyzed as a function of frequency and, based on the analysis, a regulation algorithm for controlling the frequency of the ultrasound generated by the ultrasound generator is determined.

Systems and methods for controlling vibrations of an ultrasonic handpiece generate an AC drive signal applied to a transducer of the ultrasonic handpiece to vibrate a tip of the ultrasonic handpiece. A property relating to a stiffness of tissue being contacted by the vibrating tip is determined based on a measured voltage and a measured current of the AC drive signal. A target displacement for the tip is determined based on the tissue property, and the AC drive signal is adjusted to achieve the determined target displacement.

A mist inhaler device (200) for generating a mist for inhalation by a user. The device comprises a mist generator device (201) and a driver device (202). The driver device (202) is configured to drive the mist generator device (201) at an optimum frequency to maximise the efficiency of mist generation by the mist generator device (201).

A vibration control device of a plate-like member 11 includes: a plurality of piezoelectric element actuators 14; at least one piezoelectric element sensor 15; and a control circuit 17 that performs feedback control of operation of the piezoelectric element actuators 14 based on an output voltage of the piezoelectric element sensor 15 so as to suppress vibration of the plate-like member 11. A layout of the piezoelectric element sensor 15 and the piezoelectric element actuators 14 is set such that anti-resonance occurs in an output voltage of the piezoelectric element sensor 15 in a range where the vibration frequency of the plate-like member 11 is equal to or less than a predetermined value. Therefore, generation of noise can be prevented at the frequency. As a result, a gain can be increased at a control target frequency. Therefore, vibration can be suppressed, and noise can be reduced.

A nebulizer has an aperture plate, a mounting, an actuator, and an aperture plate drive circuit (2-4). A controller measures an electrical drive parameter at each of a plurality of measuring points, each measuring point having a drive frequency; and based on the values of the parameter at the measuring points makes a determination of optimum drive frequency and also an end-of-dose prediction. The controller performs a short scan at regular sub-second intervals at which drive current is measured at two measuring points with different drive frequencies. According to drive parameter measurements at these points the controller determines if a full scan sweeping across a larger number of measuring points should be performed. The full scan provides the optimum drive frequency for the device and also an end of dose indication.

A vibration damping system for a charged particle beam apparatus according to the present invention includes a column through which a charged particle beam passes, a vibration detection unit that detects vibration of the column, a damping mechanism that applies vibration to the column to suppress the vibration of the column, and a control device that controls the damping mechanism. The control device includes a damping gain control unit that amplifies a detection signal of the vibration detection unit with a set amplification factor and outputs an amplified detection signal as a control signal to the damping mechanism, and a saturation suppression unit that adjusts a feedback gain value of the damping gain control unit according to a detection signal of the vibration detection unit, a signal of the damping mechanism, and a maximum output value and a minimum output value of the damping mechanism.

An input apparatus includes an operating unit on which an input operation is performed by an operator, a detecting unit configured to detect the input operation performed on the operating unit, an actuator configured to impart vibration to the operating unit, and a control unit configured to supply a drive signal to the actuator according to a result of detection performed by the detecting unit. The control unit supplies, as the drive signal, a single pulse signal including a triangular wave or a sine wave and having a signal waveform in which a rising interval and a falling interval are asymmetric about a peak position to the actuator.

In a vibration unit, a first electrode of a sensor circuit of a control unit is electrically connected to a first external electrode of a first piezoelectric element, a second electrode of the sensor circuit is electrically connected to a second external electrode of the first piezoelectric element, a first electrode of a drive circuit is electrically connected to a first external electrode of a second piezoelectric element, and a second electrode of the drive circuit is electrically connected to a second external electrode of the second piezoelectric element. Only a relatively small voltage induced by an electromotive force occurring due to the flexure of the first piezoelectric element is applied to the sensor circuit. In addition, only a relatively large drive voltage to be applied to the second piezoelectric element is applied to the drive circuit.

Disclosed herein are acoustic transmission systems comprising an acoustic wave generator configured to generate an acoustic wave and propagate the acoustic wave through a tissue of a specimen, and a non-Hermitian complementary metamaterial (NHCMM) configured to add a first amount of energy amplification coherently to the acoustic wave to account for energy loss in the acoustic wave as a result of the wave propagating through the tissue of the specimen. The acoustic wave generator can be an ultrasound generator, and the tissue can be a cranium.

A method of actuating an ultrasonic drive device includes sweeping, by a first control circuit, a frequency at which an ultrasonic transducer oscillates from a predetermined frequency toward a resonant frequency, predicting, by a prediction circuit, whether or not ringing occurs based on a first parameter representing a driving state of the ultrasonic transducer, and if the prediction circuit predicts that the ringing does not occur and if a second parameter representing a frequency at which the ultrasonic transducer is driven satisfies a predetermined condition, resonantly driving, by a second control circuit, the ultrasonic transducer at a resonant frequency by PLL control.